Wonderful. Nobody said it was.
Why do sexual acts in and of themselves deserve special protection unless someone has a constitutional right to engage in anal intercourse?
Since it's hardly "special" protection, that's a complete non-starter as well - there is no compelling state interest in prosecuting you and your wife for consensual sexual acts performed in your bedroom, regardless of where you stick it. I suggest that two consenting adult men ought to enjoy the same protections that you enjoy.
But do keep trying - there may be a justification for all this in there somewhere...
The only reason you could say the state has no legitimate authority to do so is that there is a protected constitutional right to engage in that kind of behavior. If that is the case, you would have to agree that a person has a constitutional right to engage in bestiality and necrophilia. If you are willing to let the country to go in that direction in order to maintain some libertarian idea of freedom, you need to have your brain examined.
Since you appear to defend the unfettered right to be a pervert... No I won't go there. Please do not tell me that my daddy almost lost his life in Korea so that now I have to justify the action of government to restrain the acts of perverts.
Excuse me. I think I will end my discussion on this thread. The filth embedded in this libertarian mindset makes me want to puke.